DNA methylation and chromosomal rearrangements in reconstructed karyotypes of Hordeum vulgare L.

Abstract

One standard and two reconstructed barley karyotypes were used to study the influence of chromosomal rearrangements on the distribution pattern of DNA methylation detectable at the chromosome level. Data obtained were also compared with Giemsa N-bands and high gene density regions that had been previously described. The effect of chromosomal reconstruction in barley seems to be decidedly prominent in the repositioning of genomic DNA methylation along metaphase chromosomes. In comparison to the standard karyotype, the DNA methylation pattern was found to vary not only in the reconstructed chromosomes but also in the other chromosomes of the complements not subjected to structural alterations. Moreover, differences may occur between corresponding regions of homologues. Some specific chromosomal bands, including the nucleolus-organizing regions, showed a relative constancy in the methylation pattern, but this was not the case when the two satellites were combined by translocation in chromosome 6H(5H) of line T-30. Our results suggest that epigenetic changes like DNA methylation may play an important role in the overall genome reorganization following chromosome reconstruction.

Systematic Analysis of the DNA Methylase and Demethylase Gene Families in Rapeseed (Brassica napus L.) and Their Expression Variations After Salt and Heat stresses

“…DNMT2, another category of methyltransferase that is conserved in many plants, can methylate tRNA(Asp)C38 in vitro [18]. To date, DNA-MTase have already been identified and characterized in several plant species, including Arabidopsis [19], Oryza sativa [20], Daucus carota [21], Hordeum vulgare [22], Zea mays [23] and Lycopersicon esculentum [24].…”

The intergenic spacer region of the rDNA in Haplopappus gracilis (Nutt.) Gray

“…Nowadays, few data are available in the literature about the behaviour of homologous chromosomes and possible divergences. Apart from the case of the two X chromosomes in female, in which differences in the methylation pattern between homologous loci in the active versus inactive chromosome have been found (Lyon 1988;Široky et al 1998), differences between homologues after anti-5mC binding have been also observed in Allium cepa , Vicia faba (Frediani et al 1996), triticale (Castilho et al 1999), Z. biebersteiniana (Cremonini et al 2003), more recently in barley reconstructed karyotypes (Ruffini Castiglione et al 2008b) and in C. versicolor (Ruffini Castiglione et al 2009). Moreover, differences between homologues have been revealed by asymmetric puffing in polytene chromosomes Cionini et al 1982), by banding techniques (Sumner 1990) and after cytological hybridization with specific DNA sequences both in plants (Durante et al 1977;Loiero et al 1982) and in animals (Hennen et al 1975;London-Vallejo et al 2001).…”

The DNA methylation level against the background of the genome size and t-heterochromatin content in some species of the genusSecale L

“…The lack of relationships between the t-heterochromatin content and the level of global cytosine methylation in Secale may be also explained by the fact, that not only DNA methylation but also other epigenetic mechanisms are involved in maintaining the constitutive heterochromatin state ( Soppe et al, 2002 ). The evidence comes from the studies on barley, in which differences in chromosomal distribution of constitutive heterochromatin and 5-mC pattern were found ( Castiglione et al, 2008 ).…”